The present invention relates to obtaining glycerol esters of fatty acids from plant, animal and marine materials.
It is well-known that many diverse materials contain glycerol esters of fatty acids which are comprised primarily of triglycerides and which are commonly known as oils and fats. Oils are generally characterized as being liquid at ambient temperature whereas fats are generally characterized as being solid or semi-solid at ambient temperature.
Many oil- and fat-containing materials include components associated with glycerol esters of fatty acids which are of benefit in various ways. For example, associated with the esters may be valuable free fatty acids such as omega-3 fatty acids which are highly unsaturated fatty acids and which are of interest and gaining attention as therapeutic and pharmacological agents, particularly in the treatment of cardiovascular conditions and diseases. Omega-3 fatty acids are found in high levels in fish oil, but these fatty acids may be found also in such diverse materials as common beans, cauliflower, purslane, legumes and nuts and seeds.
Many oil- and fat-containing materials with which omega-3 fatty acids are associated, however, contain only relatively small amounts of glycerol esters of fatty acids, i.e., on the order of from less than 1% to 3% of the esters by weight, but the amount of omega-3 fatty acids included with the esters is relatively high. Although obtaining the omega-3 fatty acids from such materials would be of value, due to the low amounts of the esters in these materials, obtaining the esters and the omega-3 fatty acids, is not believed to have been heretofore practical or economical. Likewise, efficient and accurate quantitative determination of amounts of oils and fats contained in various materials can be of importance in regard to quality control procedures, or for meeting labeling requirements, for example.
Methods which utilize direct solvent extraction are known for analytical quantitative determination of the amounts of oils and fats in materials which contain relatively low amounts of the same. One such method is the Goldfisch Extractor method, which is a direct solvent extraction method as described in A.O.C.S. Official Method Aa 4-38 (1984). Another direct extraction method is known as the Soxhlet Extraction method and is described in AOAC Official Methods of Analysis (1984) at pages 242-243. A further method, a gravimetric method, which utilizes an extraction tube known as the Mojonnier extraction tube, comprises solvent extraction from a sample prepared with alcohol and hydrochloric acid and ether, with oil extraction performed by petroleum ether, as described in AOAC Official Methods of Analysis (1984) at page 160.